Image forming apparatus including cover having opening that allows toner cartridge to pass therethrough but does not allow drum cartridge to pass therethrough

An image forming apparatus comprising:

• a main casing having an opening;
• a cover movable between:
• a closed position in which the cover closes the opening;
• and
• an open position in which the first opening is opened;
• a drum cartridge comprising a photosensitive drum extending in a longitudinal direction, the drum cartridge being attachable to and detachable from the main casing through the opening in a state where the cover is in the open position;
• and
• a toner cartridge configured to accommodate toner therein, the toner cartridge being attachable to and detachable from the drum cartridge,
• wherein, in a state where the drum cartridge is accommodated in the main casing, the drum cartridge is pivotally movable between:
• a drum locking position in which the drum cartridge is locked relative to the main casing;
• and
• a drum unlocking position in which the drum cartridge is not locked relative to the main casing,
• wherein, in a state where the cover is in the first open position and the drum cartridge is in the drum unlocking position, the drum cartridge is detachable from the main casing in a predetermined direction crossing the longitudinal direction,
• wherein the main casing comprises an abutment portion contacting a part of the drum cartridge when the drum cartridge is moved in the predetermined direction from the drum locking position, and
• wherein, in a state where the first cover is in the first open position and the drum cartridge is in the drum locking position, the drum cartridge is not detachable from the main casing in the predetermined direction.